Renal artery stenosis is an important clinical problem which often results in systemic hypertension arid contributes to chronic renal failure with loss of renal mass. Current techniques to treat renal artery stenosis have been generally unsuccessful especially when the area of narrowing is at or close to the renal artery ostium. Current balloon angioplasty techniques can achieve initial favorable responses but chronic recurrence (within the first six months) due to treatment site restenosis occurs in greater than 70% of individuals. Expandable intravascular prostheses (stents) have been proposed as a catheter-based solution to the problem of chronic restenosis in patients with ostial renal artery narrowing. We evaluated the acute deployment factors and chronic healing responses after implantation of a metallic tubular-slotted balloon expandable stent in normal sheep renal arteries. We found that careful adjustment of operator technique is required to correctly implant balloon expandable stents in the renal ostium without migration or extension into the aorta. Vasospasm was occasionally encountered but thrombus formation was absent and rapid endothelialization was uniform after correct positioning of stents in the renal artery ostium. We conclude that this study has helped to provide useful operational and pathological insights concerning the use of stents as a treatment modality in patients with renal artery stenosis.